DSpace collection: 期刊論文

Vibration of Arch Bridges Due to Moving Loads and Vertical Ground Motions

Thu, 11 Jul 2013 03:19:51 GMT

title: Vibration of Arch Bridges Due to Moving Loads and Vertical Ground Motions abstract: This paper is focused on the vibration in a two‐hinged arch bridge subjected to the combined action of moving loads and vertical ground excitations. The arch bridge is modeled as a flat‐rise parabolic arch with constant sectional properties along the horizontal axis of span, and the train loadings over it as a sequence of identical lumped loads with constant intervals. To investigate such a dynamic problem, a single span bridge with non‐homogeneous time‐dependent boundary conditions, the quasi‐static decomposition method is employed to decompose the deflection response of the arch into quasi‐static deflection and the dynamic component of deformation. Then one can analytically derive the closed form solution of quasi‐static deflection for the arch bridge shaken by vertical support excitations. Throughout the parameter studies, the present results indicate that the maximum acceleration response on the arch bridge relates to: (1) the vibration mode that has been excited, (2) the time lag until moving loads begin to enter the bridge during the acting time of earthquakes, and (3) the rise to span ratio of the arch.

Recent developments in geometrically nonlinear and postbuckling analysis of framed structures

Fri, 31 May 2013 02:48:04 GMT

title: Recent developments in geometrically nonlinear and postbuckling analysis of framed structures abstract: Geometric nonlinear analysis of structures is not a simple extension from its counterpart of linear analysis. In this article, some research works conducted primarily in the past two decades on the geometric nonlinear analysis of framed structures that are readily available to the authors, including, in particular, those conducted by the senior author and coworkers, will be briefly reviewed. To highlight the key features of geometric nonlinear analysis, each of the papers cited will be reviewed according to one or more of the following categories: a) analytical or semi-analytical works, b) formulation of incremental nonlinear theory, c) discrete vs connected element and procedure of assembly, d) joint equilibrium conditions in the deformed configuration, e) rigid body test for nonlinear finite elements, f) key phases in incremental-iterative analysis, g) force recovery procedure, h) strategy for incremental-iterative approaches, i) rigid body-qualified geometric stiffness matrix, j) formulation and simulation for curved beam problems, k) special considerations for truss structures, and l) other related considerations. Throughout this article, emphasis will be placed on the theories and procedures leading to solution of the load-deflection response of structures, which may involve multi-looping curves in the postbuckling range. In fact, a nonlinear analysis using incremental-iterative schemes need not be as complicated as we think. If due account can be taken of the rigid body behaviors at each stage, then the whole process of incremental-iterative analysis can be made simpler and more efficient. Even when the postbuckling behavior of structures is of concern, the use of an accurate elastic stiffness matrix plus a rigid-body-qualified geometric stiffness matrix can always yield satisfactory results. There are 122 references cited in this review article.

簡支橋受車行的衝擊係數探討

Tue, 12 Mar 2013 04:58:31 GMT

title: 簡支橋受車行的衝擊係數探討

軌道力學導論(3)：版式軌道系統受車行的輪軌互制反應

Tue, 12 Mar 2013 04:58:19 GMT

title: 軌道力學導論(3)：版式軌道系統受車行的輪軌互制反應

高速列車穿越連續橋之車橋互動行為

Tue, 12 Mar 2013 04:58:07 GMT

title: 高速列車穿越連續橋之車橋互動行為

高速列車引致的地表振動

Tue, 12 Mar 2013 04:57:48 GMT

title: 高速列車引致的地表振動

簡支梁受移動列車載重之減振分析

Wed, 19 Oct 2011 15:21:25 GMT

title: 簡支梁受移動列車載重之減振分析

軌道力學導論之二：無限長彈性基礎梁之基本動態理論

Wed, 19 Oct 2011 15:21:08 GMT

title: 軌道力學導論之二：無限長彈性基礎梁之基本動態理論

軌道力學導論之一：彈性基礎梁受移動力量作用之基本理論

Wed, 19 Oct 2011 15:20:59 GMT

title: 軌道力學導論之一：彈性基礎梁受移動力量作用之基本理論

Vibration reduction for cable-stayed bridges traveled by high-speed trains

Wed, 19 Oct 2011 15:20:45 GMT

title: Vibration reduction for cable-stayed bridges traveled by high-speed trains

Vibration of Simply Supported Compound Beams to Moving Loads

Wed, 19 Oct 2011 15:20:40 GMT

title: Vibration of Simply Supported Compound Beams to Moving Loads

Vibration of Parabolic Tied-Arch Beams Due to Moving Loads

Wed, 19 Oct 2011 15:20:36 GMT

title: Vibration of Parabolic Tied-Arch Beams Due to Moving Loads

Vertical accelerations of simple beams due to successive loads traveling at resonant speeds

Wed, 19 Oct 2011 15:20:27 GMT

title: Vertical accelerations of simple beams due to successive loads traveling at resonant speeds

Vehicle-bridge interactions and applications to high speed rail bridges

Wed, 19 Oct 2011 15:20:23 GMT

title: Vehicle-bridge interactions and applications to high speed rail bridges

Stability of Tapered I-Beams Under Torsional Moments

Wed, 19 Oct 2011 15:20:09 GMT

title: Stability of Tapered I-Beams Under Torsional Moments

RC構件的韌性補強方法與設計，實例之二：韌性補強措施

Wed, 19 Oct 2011 15:19:56 GMT

title: RC構件的韌性補強方法與設計，實例之二：韌性補強措施

RC構件的韌性補強方法與設計，實例之一：補強方法概述

Wed, 19 Oct 2011 15:19:51 GMT

title: RC構件的韌性補強方法與設計，實例之一：補強方法概述

Mechanism of resonance and cancellation for train-induced vibrations on bridges with elastic bearings

Wed, 19 Oct 2011 15:19:46 GMT

title: Mechanism of resonance and cancellation for train-induced vibrations on bridges with elastic bearings

An element for analysing vehicle-bridge systems considering vehicle's pitching effect

Tue, 05 Jan 2010 01:01:31 GMT

title: An element for analysing vehicle-bridge systems considering vehicle's pitching effect abstract: Vehicle–bridge interaction (VBI) elements that were derived by treating a vehicle as discrete sprung masses lack the capability to simulate the pitching effect of the car body on the vehicle and bridge responses. To overcome this drawback, a vehicle is modelled instead as a rigid beam supported by two spring-dashpot units in this paper. The equations of motion written for the vehicle and the bridge (beam) elements are coupled due to the existence of the interacting forces at contact points. To resolve this problem, the vehicle equations are first reduced to equivalent stiffness equations using Newmark's discretization scheme. Then, the vehicle degrees of freedom (DOFs) are condensed to those of the beam elements in contact. The rigid vehicle–bridge interaction elements derived can be effectively used in computation of not only the bridge response, but also the vehicle response, as required in design of high-speed railroad bridges.

Impact response of high speed rail bridges and riding comfort of rail cars

Tue, 05 Jan 2010 01:01:22 GMT

title: Impact response of high speed rail bridges and riding comfort of rail cars abstract: The vibration of simple and three-span continuous beams traveled by trains moving at high speeds is studied in this paper. Central to this study is the adoption of a dimensionless speed parameter S, defined as the ratio of the exciting frequency of the moving vehicles to the fundamental frequency of the beam. The numerical studies indicate that the moving load model is generally accurate for simulating the bridge response. However, the use of the sprung mass model is necessary whenever the riding comfort of rail cars is of concern. If the characteristic length, rather than the span length, is used for the continuous beam, then both the simple and continuous beams will reach their peak responses at the same critical speed S, when traveled by wheel loads of constant intervals. The rail irregularity, ballast stiffness, suspension stiffness and suspension damping can drastically affect the riding comfort of rail cars traveling over simple beams. Their effects are comparatively small for continuous beams. In conclusion, the design of a high speed rail bridge is governed primarily by the conditions of serviceability, rather than by strength.

A simple nonlinear triangular plate element and strategies of computation for nonlinear analysis

Tue, 05 Jan 2010 01:01:15 GMT

title: A simple nonlinear triangular plate element and strategies of computation for nonlinear analysis abstract: According to the rigid body rule, for a solid member subjected to rigid body rotations, the initial forces acting on the member that form an equilibrating set must rotate following the rigid body rotations, while remaining unchanged in magnitude. Such a rule is physically intuitive and is employed in this paper to derive an approximate geometric stiffness matrix for a three-node triangular plate element (TPE) containing three translational and three rotational degrees of freedom (DOFs) at each node. An element such as this is attractive, since it can be easily used along with the 12-DOF beam element to simulate various plate and shell assemblies. Another advantage with the geometric stiffness matrix derived is that it can be explicitly given, which renders numerical integrations unnecessary. Finally, the element and procedure proposed are demonstrated to be robust in that solutions of good accuracy can always be obtained if a practically fine mesh has been used, and that the solutions converge rapidly to the exact one upon mesh refinement.